Calorie Deficit Calculator
Find the daily calories to hit a target weekly weight-loss rate.
Results update as you type.
About this calculator
A calorie deficit calculator works out how many calories to eat below your maintenance level to lose weight at a chosen pace. It uses the widely-used approximation that a kilogram of body fat stores about 7,700 calories (3,500 per pound), so a 500-calorie daily deficit loses roughly half a kilogram (about a pound) a week. Add your current and goal weight to estimate how long it will take.
Frequently asked questions
How big a calorie deficit is safe?
A deficit of 500–750 calories a day (0.5–0.75 kg or about 1–1.5 lb per week) is a common, sustainable target. Very aggressive deficits risk muscle loss and are hard to maintain, so most guidance keeps loss to about 1% of body weight per week.
Why 7,700 calories per kilogram?
A kilogram of stored body fat holds roughly 7,700 calories (a pound about 3,500). Dividing your weekly deficit by seven gives the daily deficit this calculator subtracts from your maintenance calories.
Is weight loss exactly this linear?
No. The 3,500-calorie rule is an approximation. As you lose weight your maintenance calories fall, water shifts and metabolism adapts, so real loss usually slows over time. Treat the estimate as a starting point and adjust.
Results are estimates for general guidance only, not financial, medical or tax advice.